全文获取类型
收费全文 | 18326篇 |
免费 | 1442篇 |
国内免费 | 131篇 |
专业分类
耳鼻咽喉 | 223篇 |
儿科学 | 518篇 |
妇产科学 | 301篇 |
基础医学 | 2338篇 |
口腔科学 | 259篇 |
临床医学 | 2025篇 |
内科学 | 4592篇 |
皮肤病学 | 236篇 |
神经病学 | 1310篇 |
特种医学 | 697篇 |
外科学 | 2817篇 |
综合类 | 280篇 |
一般理论 | 9篇 |
预防医学 | 1276篇 |
眼科学 | 634篇 |
药学 | 1116篇 |
中国医学 | 50篇 |
肿瘤学 | 1218篇 |
出版年
2023年 | 89篇 |
2022年 | 134篇 |
2021年 | 280篇 |
2020年 | 185篇 |
2019年 | 354篇 |
2018年 | 359篇 |
2017年 | 298篇 |
2016年 | 304篇 |
2015年 | 330篇 |
2014年 | 505篇 |
2013年 | 761篇 |
2012年 | 1072篇 |
2011年 | 1033篇 |
2010年 | 647篇 |
2009年 | 637篇 |
2008年 | 1071篇 |
2007年 | 1159篇 |
2006年 | 1165篇 |
2005年 | 1103篇 |
2004年 | 1068篇 |
2003年 | 1017篇 |
2002年 | 947篇 |
2001年 | 305篇 |
2000年 | 292篇 |
1999年 | 253篇 |
1998年 | 218篇 |
1997年 | 204篇 |
1996年 | 150篇 |
1995年 | 202篇 |
1994年 | 157篇 |
1993年 | 127篇 |
1992年 | 209篇 |
1991年 | 169篇 |
1990年 | 173篇 |
1989年 | 165篇 |
1988年 | 174篇 |
1987年 | 164篇 |
1986年 | 147篇 |
1985年 | 130篇 |
1984年 | 133篇 |
1983年 | 141篇 |
1982年 | 138篇 |
1981年 | 124篇 |
1980年 | 121篇 |
1979年 | 99篇 |
1978年 | 99篇 |
1977年 | 108篇 |
1976年 | 89篇 |
1975年 | 64篇 |
1974年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
David H. Barlow Consultant Linda D. Cardozo Consultant Roger M. Francis Consultant Physician Mary Griffin Clinical Assistant David M. Hart Consultant Elaine Stephens Clinical Nurse Specialist David W. Sturdee Consultant 《BJOG : an international journal of obstetrics and gynaecology》1997,104(1):87-91
Objective To provide information on the extent of problems of urogenital ageing in older British women.
Design A MORI survey of a representative population sample of older British women.
Setting Home interviews.
Participants Two thousand and forty-five women aged 55–85+.
Results Urogenital symptoms had affected 48.8% of the women at some time, but no more than 11% were currently affected by individual symptoms; however, these were often of long duration. The majority (73%) were not sexually active, with lack of a partner being a factor for many. There was also a decreasing prevalence of sexual activity with increasing age. Those sexually active in the 65–74 year old age group ( n = 148 ) tended to have a similar sexual frequency (at least once per month) compared with the younger women studied. Approximately 12% of those who reported dyspareunia and/or vaginal dryness claimed a severe problem; 33% did not seek professional advice and 36% resorted to an over the counter remedy. Use of hormone replacement therapy was generally of relatively short duration. There was a declining gradient of ever-use with age.
Conclusions The extent of significant urogenital symptoms is relatively low, but some women are seriously affected and use self-help as well as professional assistance. The extent of sexual activity in older women and factors affecting this have been defined, and the effect of urogenital symptoms on sexual activity demonstrated. 相似文献
Design A MORI survey of a representative population sample of older British women.
Setting Home interviews.
Participants Two thousand and forty-five women aged 55–85+.
Results Urogenital symptoms had affected 48.8% of the women at some time, but no more than 11% were currently affected by individual symptoms; however, these were often of long duration. The majority (73%) were not sexually active, with lack of a partner being a factor for many. There was also a decreasing prevalence of sexual activity with increasing age. Those sexually active in the 65–74 year old age group ( n = 148 ) tended to have a similar sexual frequency (at least once per month) compared with the younger women studied. Approximately 12% of those who reported dyspareunia and/or vaginal dryness claimed a severe problem; 33% did not seek professional advice and 36% resorted to an over the counter remedy. Use of hormone replacement therapy was generally of relatively short duration. There was a declining gradient of ever-use with age.
Conclusions The extent of significant urogenital symptoms is relatively low, but some women are seriously affected and use self-help as well as professional assistance. The extent of sexual activity in older women and factors affecting this have been defined, and the effect of urogenital symptoms on sexual activity demonstrated. 相似文献
122.
Preclinical in vivo antitumor activity of vinflunine, a novel fluorinated Vinca alkaloid 总被引:1,自引:0,他引:1
Anna Kruczynski Francis Colpaert Jean-Pierre Tarayre Pierre Mouillard Jacques Fahy Bridget T. Hill 《Cancer chemotherapy and pharmacology》1998,41(6):437-447
Vinflunine, or 20′,20′-difluoro-3′,4′-dihydrovino‐relbine, is a novel Vinca alkaloid obtained by hemisynthesis using superacidic chemistry. The most impressive structural modification of this vinorelbine
derivative was the selective introduction of two fluorine atoms at the 20′ position, a part of the molecule previously inaccessible
by classic chemistry. The antitumor activity of vinflunine was evaluated against a range of transplantable murine and human
tumors. Vinflunine exhibited marked activity against murine P388 leukemia grafted i.v. when given i.p. in single or multiple
doses according to various schedules or in single i.v. or p.o. doses. Increases in life span achieved with vinflunine, as
assessed by T/C ratios, ranged from 200% to 457% and proved markedly superior to those of 129–186% obtained with the other
Vinca alkaloids tested. Against s.c.-implanted B16 melanoma, multiple i.p. administration of vinflunine proved active in terms
of both survival prolongation and tumor growth inhibition, with optimal T/C values and relative areas under the tumor growth
curves (rAUC) being 24% and 36%, respectively. The extent of this activity was superior to that noted for vinorelbine under
the same experimental conditions. Growth inhibition of human tumor xenografts LX-1 (lung) and MX-1 (breast) was also observed
following four weekly i.p. injections of vinflunine as reflected by optimal T/C values of 23% and 26%, respectively, and significant
differences in the rAUCs noted for treated versus control animals. It was also noticeable that vinflunine induced considerably
more prolonged inhibitory effects on tumor growth than did vinorelbine. These results demonstrate that vinflunine is well
tolerated and is definitively active against a range of experimental animal tumor models. Vinflunine activity has been documented
in terms of both survival prolongation and tumor growth inhibition, with definite superiority over vinorelbine being shown
in each tumor model evaluated.
Received: 13 July 1997 / Accepted: 21 October 1997 相似文献
123.
Federle MP Chezmar JL Rubin DL Weinreb JC Freeny PC Semelka RC Brown JJ Borello JA Lee JK Mattrey R Dachman AH Saini S Harmon B Fenstermacher M Pelsang RE Harms SE Mitchell DG Halford HH Anderson MW Johnson CD Francis IR Bova JG Kenney PJ Klippenstein DL Foster GS Turner DA 《Journal of magnetic resonance imaging : JMRI》2000,12(1):186-197
The short-term safety of mangafodipir trisodium (MnDPDP) injection was studied in 546 adults with known or suspected focal liver lesions. An initial contrast-enhanced computed tomography examination was followed by unenhanced magnetic resonance imaging (MRI), injection of MnDPDP (5 micromol/kg), and enhanced MRI. Adverse events were reported for 23% of the patients; most were mild to moderate in intensity, did not require treatment, and were not drug related. The most commonly reported adverse events were nausea (7%) and headache (4%). The incidence of serious adverse events was low (nine events in six patients) and not drug related. Injection-associated discomfort was reported for 69% of the patients, and the most commonly reported discomforts included heat (49%) and flushing (33%). Changes in laboratory values and vital signs were generally transient, were not clinically significant, and did not require treatment. There were no clinically significant short-term risks from exposure to MnDPDP. 相似文献
124.
A patient acceptability study was conducted using patient-controlled intranasal diamorphine. Patients undergoing nonemergency orthopaedic or gynaecological surgery self-administered intranasal diamorphine for 24 h postoperatively. Pain, pain relief, sedation, respiratory rate, nausea and vomiting were assessed regularly. After 24 h, patients and their attending nurses completed a questionnaire assessing satisfaction and practical aspects of the technique. Satisfaction was reported as good or complete by 69% of patients and 69% of nurses. Pain relief was assessed as better than expected by 45% of patients and better than normal by 50% of nurses. Seventy-nine per cent of patients would be pleased to use patient-controlled intranasal diamorphine again and 89% of nurses would be happy for their patients to use it again. Sedation was uncommon and mild and there were no episodes of significant respiratory depression. Fifty-three per cent of patients reported no nausea and 74% did not vomit at any stage. There were seven withdrawals, four due to problems with the device and three due to therapeutic problems. The nasal spray may need modification to improve reliability. However, we found patient-controlled intranasal analgesia an effective technique, which was well tolerated by patients and nurses and was without unpleasant side-effects. Further work to determine how it performs compared with intramuscular or intravenous analgesia is now needed. 相似文献
125.
Female Long-Evans rats exhibit stable individual differences in maternal behaviours such as pup licking/grooming and arched-back nursing posture (LG-ABN). These variations in maternal behaviour are accompanied by differences in lactation-induced increases in oxytocin receptor levels in brain regions known to mediate the expression of maternal care in this species (i.e. the bed nucleus of the stria terminalis, the medial preoptic area and the lateral septum). Oxytocin receptor levels in the central nucleus of the amygdala were significantly higher in high compared to low LG-ABN females regardless of reproductive status. These findings suggest that individual differences in maternal behaviour may be directly related to variations in oxytocin receptor expression. 相似文献
126.
Purpose: To test the influence of nerve growth factor (NGF) on striatal glutathione (GSH) content and the activities of GSH-related enzymes from quinolinic acid-lesioned rats. Methods: Rats were intrastriatally injected with QA and NGF. Enzymatic and GSH assays were performed one week later. Results: NGF prevented the QA-induced decline in glutathione reductase activity and GSH content. Conclusions: NGF is able to prevent some of the disturbances induced by the excitotoxic insult in the striatal GSH metabolism. 相似文献
127.
Tyvin Rich Pasquale F Innominato Julie Boerner M Christine Mormont Stefano Iacobelli Benoit Baron Claude Jasmin Francis Lévi 《Clinical cancer research》2005,11(5):1757-1764
PURPOSE: Incapacitating symptom burden in cancer patients contributes to poor quality of life (QOL) and can influence treatment outcomes because of poor tolerance to therapy. In this study, the role of circulating cytokines in the production symptoms in cancer patients is evaluated. EXPERIMENTAL DESIGN: Eighty patients with metastatic colorectal cancer with either normal (group I, n = 40) or dampened (group II, n = 40) 24-hour rest/activity patterns measured by actigraphy were identified. Actigraphy patterns were correlated with QOL indices, serum cortisol obtained at 8:00 a.m. and 4:00 p.m. and with serum levels of transforming growth factor-alpha, tumor necrosis factor-alpha, and interleukin 6 (IL-6) obtained at 8:00 a.m. and analyzed in duplicate by ELISA. Cytokine levels and survival were also correlated. RESULTS: Group II patients had significantly higher pre treatment levels of all three cytokines, displayed significantly poorer emotional and social functioning, had higher fatigue, more appetite loss, and poorer performance status compared with group I patients. Transforming growth factor-alpha (TGF-alpha) and IL-6 were significantly increased in the patients with WHO performance status >1 and in those with appetite loss. Fatigue was significantly associated with elevated TGF-alpha only. IL-6 was increased in those patients with extensive liver involvement and multiple organ replacement, and it was significantly correlated with dampened cortisol rhythm. In a multivariate analysis, IL-6 was correlated with poor treatment outcome. CONCLUSIONS: Significant correlations were found between serum levels of TGF-alpha and IL-6, circadian patterns in wrist activity and serum cortisol and tumor-related symptoms in patients with metastatic colorectal cancer. These data support the hypothesis that some cancer patient's symptoms of fatigue, poor QOL, and treatment outcome are related to tumor or host generated cytokines and could reflect cytokine effects on the circadian timing system. This interplay between cytokine signaling pathways, the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, and efferent pathways of the suprachiasmatic nucleus that control circadian physiology, opens the way to new rational interventions for symptom management in cancer patients. 相似文献
128.
Mitch Dowsett Steve R Ebbs J Michael Dixon Anthony Skene Clive Griffith Irene Boeddinghaus Janine Salter Simone Detre Margaret Hills Susan Ashley Stephen Francis Geraldine Walsh Ian E Smith 《Journal of clinical oncology》2005,23(11):2477-2492
PURPOSE: To investigate the relationships between biomarker changes in breast cancer during neoadjuvant (preoperative) endocrine therapy. PATIENTS AND METHODS: The IMPACT trial compared the preoperative use of tamoxifen with anastrozole alone or in combination in postmenopausal women (n = 330) with primary breast cancer. Biomarkers were measured in tumor biopsy specimens taken at baseline, and after 2 and 12 weeks of treatment. RESULTS: 52 (93%) of 56, 46 (85%) of 54, and 37 (84%) of 44 patients in the anastrozole, tamoxifen, and combination groups, respectively. There was a significantly greater suppression of Ki67 in the anastrozole-treated group than in the tamoxifen- or combination-treated groups, which is parallel to the greater efficacy seen for anastrozole over these two treatments in the Arimidex, Tamoxifen, Alone or in Combination adjuvant trial. A positive relationship was noted between estrogen-receptor level and Ki67 suppression in all patients. Ki67 was reduced to a greater extent in progesterone receptor-positive tumors compared with progesterone receptor-negative tumors. HER-2-negative tumors tended to show a greater reduction in Ki67 compared with HER-2-positive tumors, but the difference was only significant in the tamoxifen group after 2 weeks, and in the anastrozole group after 12 weeks. CONCLUSION: These results confirm the value of Ki67 as a molecular marker, and provide information regarding the relationships between treatment-induced changes in Ki67 and other important biomarkers. Studies such as this should help integrate agents targeted at growth factor signaling with endocrine agents in breast cancer. 相似文献
129.
Mary Feng Siavash Jabbari Alexander Lin Carol R Bradford Douglas B Chepeha Theodoros N Teknos Francis P Worden Christina Tsien Matthew J Schipper Gregory T Wolf Laura A Dawson Avraham Eisbruch 《Radiotherapy and oncology》2005,77(1):32-38
BACKGROUND AND PURPOSE: Predictive factors for local-regional (LR) failures after parotid-sparing, Intensity modulated (IMRT) or 3D conformal radiotherapy for head and neck (HN) cancers were assessed. PATIENTS AND METHODS: One hundred and fifty-eight patients with mostly stages III-IV HN squamous cell carcinoma underwent curative bilateral neck irradiation aimed at sparing the parotid glands. Patient, tumor, and treatment factors were analyzed as predictive factors for LR failure. RESULTS: Twenty-three patients had LR recurrence (19 in-field and four marginal). No differences were found in the doses delivered to the PTVs of patients with or without in-field recurrences. In univariate analysis, tumor site was highly predictive for LR failure in both postoperative and definitive RT patients. In postoperative RT patients, pathologic tumor size, margin status, extracapsular extension (ECE) and number of lymph node metastases, were also significantly predictive. Multivariate analysis showed tumor site (oropharynx vs. other sites) to be a significant predictor in all patients, and involved margins and number of involved lymph nodes in postoperative patients. CONCLUSIONS: Clinical rather than dosimetric factors predicted for LR failures in this series, and were similar to those reported following standard RT. These factors may aid in the selection of patients for studies of treatment intensification using IMRT. 相似文献
130.
The authors report on three patients suffering from coexistent trigeminal neuralgia (TGN) and Charcot-Marie-Tooth disease who, based on preoperative magnetic resonance tomographic angiography findings, underwent microvascular decompression. All patients had demonstrable neural compression and all experienced immediate postoperative pain relief. Symptoms recurred in one patient and required a second procedure in the form of a neurotomy. Two patients suffered from bilateral TGN. When a patient with TGN suffers coexistent neurological disease and experiences bilateral symptoms, preoperative imaging and subsequent decompressive surgery may avoid the unacceptable risk of morbidity associated with bilateral ablative procedures. 相似文献